66 research outputs found
Atheists on the Santiago way : examining motivations to go on pilgrimage
In the past 30 years, the camino to Santiago de Compostela has been recreated as an eclectic pilgrimage, open to both religious and atheist travelers. Following previous work on motivational orientations and religion, we conducted a study examining atheist versus religious pilgrims' motivations to walk the Santiago way. We assessed pilgrims (N = 360) at various parts of the northern Spanish camino using a questionnaire that measured motivations to go on pilgrimage. In addition, we measured levels of positive and negative affect, physical exertion, and emotional problems. Atheists scored significantly lower on community and religious types of motivations. However, in several measures no differences were found between groups. We suggest that both atheist and religious pilgrims are exploring forms of horizontal and vertical transcendence characterized by a desire to connect to nature and one's deeper sel
Peritidal cyclic sedimentation from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza, Argentina
The La Manga Formation consists of marine carbonates and represents most of the sedimentary record of the Callovian-Oxfordian in the Neuquén Basin. Three localities in the southern Mendoza province were studied and their cyclicity was determined by means of facies analysis and their vertical arrangement. Facies of inner ramp, that were deposited in extremely shallow-water environments with intermittent subaerial exposures have been broken down into shallow subtidal, and intertidalesupratidal environments. Shallow subtidal facies are arranged into decimetre scale upward-hallowing cycles composed of marls, laminated or massive mudstones or bioclastic wackestones and intraclastic wackestone-packstones. Intertidal-supratidal centimetre-scale cycles consist of an upward-shallowing succession of restricted facies, overlaid by horizontal or crinkle microbial laminites, flat pebble conglomerates or breccias beds. The defined cycles show a shallowing upward trend in which the evidence of relative sea-level lowering is accepted. The interpretation of Fischer plots allowed the recognition of changes in accommodation space
Preliminary characterization of echinoderm assemblages in circalittoral and bathyal soft bottoms of the northern Alboran Sea
Echinoderms, with 7.272 species described so far (based on WORMS), provide an ecosystemic role which can be important depending on their habitat, and including tag species (Manjón-Cabeza et al., 2014; Palma-Sevilla 2015) or even dominant ones (Iken et al., 2010; Hughes et al., 2012). Despite the increasing knowledge on their taxonomy, studies on ecological and assemblage composition and structure of echinoderms are very scarce compared to those for other invertebrate groups, being this information essential for improving the knowledge on Mediterranean ecosystems (Coll et al., 2010).
The Alboran Sea, in the junction of the Atlantic Ocean and the Mediterranean Sea and the European and African continental margins, represents a biodiversity hotspot due to the overlapping of species from those basins and continents, including some endemic components (Coll et al., 2010). Regarding echinoderms of the Alboran Sea, most previous studies focussed on infralittoral bottoms, with very few for circalittoral and bathyal ones (Manjón-Cabeza et al, 2014; Sibuet, 1974). Nevertheless, these studies generally included faunistic lists (Ocaña & Pérez-Ruzafa, 2004; Manjón-Cabeza et al., 2014), sometimes with identification keys, ecological and distributional data of some species and rarely on the assemblage composition and structure (Palma-Sevilla, 2015), which represent the main aim of this study on echinoderm assemblages of circalittoral and bathyal soft bottoms of the Alboran Sea.
During the MEDITS survey expeditions (April-May 2014-2015) on board the R/V Miguel Oliver (Fig. 1), 35 samples were collected using a beam trawl (horizontal and vertical openings of 1.3 and 1.2 m, respectively, and a mesh size of 10 mm in the codend) at depths from 40 to 774 m in the Alboran Sea (Fig. 1). Hauls were done at a speed of ca. 2 knots during 5-10 (shelf stations) and 15 minutes (slope stations). Echinoderms were separated, identified to the lowest possible taxonomic leveland specimens counted and weighed to the nearest 0.5 g. Abundance and biomass data were standardized to 1000 m2 according to the sampling area of each haul.
Echinoderm assemblages were characterized according to the dominance and frequency of occurrence of species in the samples and considering different ecological indexes. Multivariate methods (CLUSTER, nMDS, SIMPER, ANOSIM) were applied, based on the Bray & Curtis similarity index, for detecting and contrastingassemblages in relation to depth and 4 geographic areas of the Alboran Sea with different influence of Atlantic waters (Occidental-Esteponato Málaga, Central-Málaga to Motril, Oriental-Motril to Almería and Alboran Island).
Fig. 1. Location of beam-trawl samples (dots) collected during 2014 and 2015 MEDITS expeditions in the northern Alboran Sea.
At present 39 taxa have been detected, mostly belonging to Ophiuroidea and Asteroidea (28.2 and 25.6% of all species, respectively), followed by Holothuroidea (23.1%), Echinoidea (17.9%) and Crinoidea (5.1%). Regarding abundance, a total of 54689 individuals have been collected, being Ophiuroidea (98.6% of all individuals), Holothuroidea (0.6%) and Crinoidea (0.4%) the top-dominant classes. Regarding biomass, ophiuroids also dominated (52.8%), followed by asteroids (16.1%) and holothuroids (15.0%). Considering other faunistic groups, echinoderms were the most abundant phyllum in the samples (60.7%) and the fifth one in biomass (7.6%). The dominant (for both abundance and biomass) and frequent genera included Ophiocten (displaying dominances >90%) Hymenodiscus, Luidia and Astropecten for asteroids, Antedon and Leptometra for crinoids, Dendrochirotida and Molpadidae for holothuroids, and Brissopsis and Echinocyamus for echinoids (Fig. 2).
Fig. 2. Some echinodermscollected in circalittoral and bathyal soft bottoms of the Alboran Sea using beam-trawl during the MEDITS expeditions. A: Ophiocten; B: Dendrochirotida sp.; C: Brissopsis; D: Anseropoda; E: Luidia.
Multivariate analyses indicated groupings of samples and significantly different echinoderm assemblages in relation to depth (RANOSIM=0.22, p0.05). Shelf assemblages displayed lower intra-group similarities (<20% similarity in SIMPER) than the slope ones (ca. 40%). Species characterizing the shelf assemblages belonged to the genera Astropecten, Antedon, Ophiothrix among others, whereas those of the slope belonged to the genera Luidia (L. sarsi), Hymenodiscus, Ophiocten, Leptometra and Amphiura
Asociaciones de moluscos de fondos sedimentarios circalitorales y batiales del norte del mar de Alborán
Molluscan assemblages from shelf and slope soft bottoms of the Alboran Sea have been
sampled with a beam trawl during 2014 and 2015 MEDITS expeditions. A total of 134 spp. of
molluscs (shell size > 3 mm) were identified, being gastropods the most diverse and dominant group.
Four main depth related assemblages were detected in multivariate analyses and characterized by
(1) Turritella communis, Chamelea striatula and Nucula sulcata for the inner shelf, (2) Timoclea
ovata, Clelandella miliaris and Neopycnodonte cochlear for the outer shelf, (3) Nassarius ovoideus,
Calumbonella suturale and N. sulcata for the upper slope and (4) Abra longicallus, Euspira fusca and
Aporrhais serresianus for the middle slope. Species richness and abundance decreased with depth,
unlike evenness and Shannon-Wiener diversity which displayed an opposite pattern. A higher spatial
variability was detected for the shelf, indicating that more assemblages may occur at this level and
further sampling is needed for covering all sedimentary habitat types of the Alboran Sea.Versión del edito
Contrasting molluscan fauna collected with beam trawl and otter trawl in circalittoral and bathyal soft bottoms of the northern Alboran Sea
The Alboran Sea display complex oceanographic, geological, ecological and biological processes, promoting a high biodiversity and complexity (Robles, 2010). On the other hand, molluscs constitute one of the most diverse and best represented invertebrate groups in this area, representing an important component of soft bottom communities, as well as the second group in abundance and biomass in demersal fisheries, with species of ecological and commercial importance worldwide (Gofas et all., 2011). The study of the molluscan assemblages is important where trawling fishing fleets operate, in order to improve fisheries assessment and move forward to an ecosystem based approach, which takes into account other components of the fishery than the target species such as non-target and protected species and habitats (Pikitch et al., 2004). Information collected on fisheries assemblages may introduce a bias depending on the fraction of the assemblage (e.g. demersal, epifaunal, infaunal) at which the sampling method is targeted, particularly in a group such as molluscs with a high variability in life strategies. The aims of this study are 1) to increase the scarce knowledge on the composition and structure of molluscan assemblages of circalittoral and bathyal soft bottoms of the Alboran Sea; and 2) to compare the information obtained on these assemblages by using two different types of sampling gears, the beam trawl and the otter trawl.
During the MEDITS trawl surveys (springs 2014 and 2015) a beam trawl (BT) (horizontal opening 1.3 x vertical opening 1.2 m, mesh size 10 mm) and an otter trawl (OT)(GOC 73) (2.5 x 21.5 m , mesh size 20 mm) were used in 35 sampling stations at depths from 40 to 800 m in the Alboran Sea. Catches were sorted to species and their individuals counted and weighed. The molluscan assemblages and species were characterized according to their dominance (%Da) and frequency of occurrence (%F). Multivariate analyses using the Bray-Curtis index were performed with presence/absence species data and quantitative data obtained with each method were standardized to a similar sampling area. ANOSIM was used for testing the differences between groups of samples according to different factors (depth and sampling type) and SIMPER for the contribution of the different species to these factors using PRIMER v6. The characterization of the different types of sampling and assemblages was done with the species richness and statistical differences tested with Kruskal-Wallis using SPSS software.
A total of 170 spp. have been collected, with 69 species collected in OT samples, mostly cephalopods (26 spp., 37.68%), followed by gastropods (25 spp., 36.23%) and bivalves (18 species, 26.10% total species of OT), being the latter the most abundant group. The top-dominant species were the bivalve Neopycnodonte cochlear and the cephalopod Alloteuthis media, whereas the most frequent ones were the cephalopods Octopus vulgaris, Todarodes sagittatus and Illex coindetii (Fig. 1 ). In beam trawl samples, 135 spp. of 6 classes were found, being gastropods the most diverse and abundant one (69 spp., 51.11% total species of BT), followed by bivalves (49 spp., 36.3%) and cephalopods (15 spp., 11.11%). The top-dominant species were the gastropods Turritella communis and Nassarius ovoideus and the bivalves Nucula sulcata and Abra longicallus, and the most frequent ones included Nucula sulcata, Nassarius ovoideus and the gastropod Euspira fusca (Figure 1).
Contrasting both methods, only 20% (34 spp.) of the species were exclusively collected in OT samples (e.g. Alloteuthis spp., I. coindetii, Loligo spp., T. sagittatus) and 57% (97 spp.) in BT samples (e.g. N. ovoideus, Timoclea ovata, N. sulcata, Clelandella miliaris). Only 23% of the species (39 spp.) were collected with both methods (e.g. Venus nux, Turritella communis, N. cochlear).
Figure 1. Some common and dominant mollusc of beam trawl (A-C, E-G) and otter trawl samples (D, H-J) collected in circalittoral and bathyal soft bottoms of the northern Alboran Sea. A) Turritella communis; B) Abra longicallus; C) Nassarius ovoideus; D) Illex coindeitii; E) Clelandella miliaris; F) Timoclea ovata; G) Nucula sulcata; H) Venus nux; I) Octopus vulgaris; J) Neopycnodonte cochlear.
Multivariate analyses clearly separated two groups of samples, each one collected with a different sampling method, and in each grouping it revealed three main mollusks assemblages in relation to depth: I) Continental shelf (CS) (40-200 m), II) Upper slope (UCS) (201-400 m), and III) and Middle slope (MCS) (400-1800 m) (Fig. 2).
Figure 2. MDS applied to presence-absence data of molluscs assemblages obtained from beam trawl and otter trawl samples collected in the northern Alboran Sea. BT: Beam trawl; OT: Otter trawl ; CS: Continental Shelf; UCS: Upper Continental Slope; MCS: Middle Continental Slope.
The continental shelf assemblage in BT samples were characterized by T. ovata, N. cochlear, N. ovoideus and T. communis, whereas O. vulgaris, Eledone moschata and I. coindetii characterized the OT samples. For the upper and middle slope assemblages, E. fusca and A. longicallus characterized the BT samples, whereas T. sagittatus and Bathypolypus sponsalis characterized the OT samples. Mean values of species richness were significantly higher when using the BT.
This study showed that OT nor BT samples can provide complete information on the whole molluscan assemblage, giving each sampling method complimentary information. The demersal and epi-benthic fractions of the community were better sampled using the otter trawl and the beam trawl, respectively. The estimates of infauna were higher using the beam trawl, but this information should be contrasted with data obtained from dredges in order to assess whether the beam trawl yield acceptable estimates of the abundance of these molluscs
Analysis of the discrepancies between the vertical reference frames of Argentina and Brazil
The vertical reference frames for Argentina and Brazil present discrepancies due to their different datums and realizations. Thus, since 2008, we have started a series of activities with the aim of unifying the Argentine and Brazilian national vertical networks (NVNs). To achieve this goal, we have connected the two NVNs at three border points by using the geodetic levelling approach. Additionally, the gravity field approach was also applied, based on a suitable representation of the geoid by considering the Earth GravitationalModel (EGM2008) in its full resolution. In this regard, 1266 co-located Global Positioning System (GPS) and levelling benchmarks regularly distributed over Argentina (612) and Brazil (654) were considered. The geodetic levelling approach shows an offset value of 54 cm, which implies that the Argentine vertical reference frame is above that of the Brazilian vertical reference frame. However, the result of the gravimetric approach shows an offset of 57 cm, which implies a difference of approximately 3 cm between both methods. Hence, since Brazil and Argentina represent a significant part of South America, the solution to the datum problem between both countries could point towards a common vertical reference frame for the Atlantic side.Facultad de Ciencias Agrarias y Forestale
Mapping density, diversity and species-richness of the Amazon tree flora
Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
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